Profiling machine tools are well known. Classically they have a sensing head (sometimes called a "tracer") with a stylus which is caused to trace over the contour of a pattern or template and give rise to signals which are processed and utilized to control motors that relatively shaft a cutting tool and workpiece so as to duplicate in the workpiece the contour of the template or pattern. The art includes hydraulic-type tracers and also electrical tracers. This invention relates to the latter type.
In electrical control systems, it is conventional for a sensing head to include two transducers which are orthogonally related to one another, and to excite them in such a way that stylus deflection will cause them to produce a signal which is proportional to the component of stylus deflection along their respective axis. The resulting signals are then, in various ways, utilized to provide a control signal for motors which drive machine tool components for the purpose of causing a cutting tool to move relative to a workpiece and thereby duplicate the contour of the template or stylus in the workpiece.
One prior art system of this type is shown in Robert H. Wenzel U.S. Pat. No. 3,582,749, issued June 1, 1971. This entire patent is incorporated herein by reference, especially for its showing of sensing heads, tracer-controlled machine tools, general construction, details and elements of circuit construction, and the theory of and operation of such tools. This invention is an improvement over the system shown in the said Wenzel patent in that its construction is simpler, and its signals enable more accurate contour duplication under many operating conditions.